Legal claims defining the scope of protection, as filed with the USPTO.
1. A method for fabricating a capacitor of a semiconductor device comprising the steps of: forming a hemispherical polysilicon layer on a bottom electrode of a storage node; nitrifying the surface of the polysilicon layer for preventing formation of a natural oxide layer on the hemispherical polysilicon layer; forming a Ta.sub.2 O.sub.5 --Al.sub.2 O.sub.3 layer as a dielectric layer on the surface nitrified polysilicon layer; and forming a plate electrode by depositing metal on the Ta.sub.2 O.sub.5 --Al.sub.2 O.sub.3 layer.
2. The method, as defined in claim 1, wherein the bottom electrode of the storage node is made in simple stack structure, cylindrical shape based double structure or complex 3-dimensional structure.
3. The method, as defined in claim 1, wherein the hemispherical grain shaped polysilicon layer is formed in a LPCVD chamber.
4. The method, as defined in claim 1, wherein a rapid thermal nitridation process is performed in an in-situ state at 750.about.900 centigrade in ammonia gas (NH3) atmosphere for 1.about.30 minutes in order to nitrify the surface of the polysilicon layer.
5. The method, as defined in claim 1, wherein an annealing process is performed in an in-situ state with plasma at 200.about.400 centigrade in ammonia gas (NH3) atmosphere in order to nitrify the surface of the polysilicon layer.
6. The method, as defined in claim 1, wherein, after formation of the polysilicon layer as the bottom electrode, storage node, HF vapor or HF solution is used in the in-situ or ex-situ state for eliminating a natural silicon oxide layer, and a Ta.sub.2 O.sub.5 --Al.sub.2 O.sub.3 layer is then deposited thereon.
7. The method, as defined in claim 6, wherein, before and after the HF surface treatment process, a compound including ammonia solution NH.sub.4 OH or sulfuric acid solution H.sub.2 SO.sub.4 can be used for treating a polysilicon surface, and the Ta.sub.2 O.sub.5 --Al.sub.2 O.sub.3 layer is, then, deposited thereon.
8. The method, as defined in claim 6, wherein the Ta.sub.2 O.sub.5 --Al.sub.2 O.sub.3 layer is formed through a CVD method to have the mole fraction ratio of Al/Ta=0.01.about.1.0.
9. The method, as defined in claim 1, wherein Ta containing chemical vapor is obtained by evaporating in the temperature range of 150.about.200 centigrade a predetermined quantity of tantalume ethylate Ta(OC.sub.2 H.sub.5).sub.5 solution supplied from vaporizer or evaporation tube through a flow controller.
10. The method, as defined in claim 8, wherein Ta containing chemical vapor is obtained by evaporating in the temperature range of 150.about.200 centigrade a predetermined quantity of tantalume ethylate Ta(OC.sub.2 H.sub.5).sub.5 solution supplied from vaporizer or evaporation tube through a flow controller.
11. The method, as defined in claim 1, wherein Al containing chemical vapor is obtained by evaporating in the temperature range of 150-200 centigrade a predetermined quantity of aluminum ethylate Al(OC.sub.2 H.sub.5).sub.3 solution supplied from vaporizer or evaporation tube through a flow controller.
12. The method, as defined in claim 8, wherein Al containing chemical vapor is obtained by evaporating in the temperature range of 150-200 centigrade a predetermined quantity of aluminum ethylate Al(OC.sub.2 H.sub.5).sub.3 solution supplied from vaporizer or evaporation tube through a flow controller.
13. The method, as defined in claim 1, wherein Al containing chemical vapor is obtained by using Al compound, aluminum hydroxide AlOH.sub.3 as a precursor.
14. The method, as defined in claim 8, wherein Al containing chemical vapor is obtained by using Al compound, aluminum hydroxide AlOH.sub.3 as a precursor.
15. The method, as defined in claim 13, wherein the Al precursor is dissolved and evaporated in an alcohol like ethanol, or butanol and water at the temperature of 100.about.500 centigrade to thereby react in a LPCVD chamber.
16. The method, as defined in claim 1, wherein the Ta.sub.2 O.sub.5 --Al.sub.2 O.sub.3 layer is deposited by inducing a surface chemical reaction in the mole fraction ratio of Al/Ta=0.01.about.1.0 along with excessive oxygen gas in the LPCVD chamber.
17. The method, as defined in claim 1, wherein, after a step of depositing the Ta.sub.2 O.sub.5 --Al.sub.2 O.sub.3 layer, a thermal treatment can be made at the temperature of 300.about.600 centigrade with N2O(or O2) plasma or UV--O.sub.3.
18. The method, as defined in claim 1, wherein an amorphous (Ta.sub.2 O.sub.5).sub.X-1 --(Al.sub.2 O.sub.3).sub.x layer is deposited in the LPCVD chamber for the first time and, then, annealed by using N.sub.2 O or O.sub.2 plasma in the in-situ state.
19. The method, as defined in claim 15, wherein an amorphous (Ta.sub.2 O.sub.5).sub.X-1 --(Al.sub.2 O.sub.3).sub.x layer is deposited in the LPCVD chamber for the first time and, then, annealed by using N.sub.2 O or O.sub.2 plasma in the in-situ state.
20. The method, as defined in claim 1, wherein the Ta.sub.2 O.sub.5 --Al.sub.2 O.sub.3 layer is deposited as a dielectric layer through a sequential multi-stage deposition process: an amorphous (Ta.sub.2 O.sub.5).sub.X-1 --(Al.sub.2 O.sub.3).sub.x layer is deposited in the LPCVD chamber for the first time and, then, annealed by using N.sub.2 O or O.sub.2 plasma in the in-situ state; and the amorphous (Ta.sub.2 O.sub.5).sub.X-1 --(Al.sub.2 O.sub.3).sub.x layer is further deposited and annealed for the second time.
21. The method, as defined in claim 15, wherein the Ta.sub.2 O.sub.5 --Al.sub.2 O.sub.3 layer is deposited as a dielectric layer through a sequential multi-stage deposition process: an amorphous (Ta.sub.2 O.sub.5).sub.X-1 --(Al.sub.2 O.sub.3).sub.x layer is deposited in the LPCVD chamber for the first time and, then, annealed by using N.sub.2 O or O.sub.2 plasma in the in-situ state; and the amorphous (Ta.sub.2 O.sub.5).sub.X-1 --(Al.sub.2 O.sub.3).sub.x layer is further deposited and annealed for the second time.
22. The method, as defined in claim 1, wherein the Ta.sub.2 O.sub.5 --Al.sub.2 O.sub.3 layer is deposited as a dielectric layer through a sequential multi-stage deposition process: an amorphous (Ta.sub.2 O.sub.5).sub.X-1 --(Al.sub.2 O.sub.3), layer is deposited in the LPCVD chamber for the first time and, then, annealed by using UV--O.sub.3 in the ex-situ state; and the amorphous (Ta.sub.2 O.sub.5).sub.X-1 --(Al.sub.2 O.sub.3).sub.x layer is further deposited and annealed with plasma for the second time.
23. The method, as defined in claim 1, wherein an amorphous (Ta.sub.2 O.sub.5).sub.X-1 --(Al.sub.2 O.sub.3).sub.x layer is deposited in the LPCVD chamber and a low temperature thermal process is, then, performed in the ex-situ state by using N.sub.2 O or O.sub.2 plasma or UV--O.sub.3 at the temperature of 300.about.600 centigrade for 1.about.30 minutes.
24. The method, as defined in claim 1, wherein, after deposition of the Ta.sub.2 O.sub.5 --Al.sub.2 O.sub.3 layer, an electrical furnace or rapid thermal process is applied as the following thermal treatment process at the temperature of 300.about.600 centigrade in N.sub.2 O or O.sub.2 atmosphere for 10.about.60 minutes.
25. The method, as defined in claim 1, wherein, after deposition of the (Ta.sub.2 O.sub.5).sub.X-1 --(Al.sub.2 O.sub.3).sub.x layer, a thermal treatment is performed in an in-situ state with plasma at the temperature of 300.about.500 centigrade in NH.sub.3 or N.sub.2 atmosphere to nitrify the (Ta.sub.2 O.sub.5).sub.X-1 --(Al.sub.2 O.sub.3).sub.x dielectric surface.
26. The method, as defined in claim 1, wherein, after deposition of the (Ta.sub.2 O.sub.5X)--(Al.sub.2 O.sub.3).sub.x layer, an electrical furnace or rapid thermal process is used at the temperature of 700.about.900 centigrade in NH.sub.3 or N.sub.2 atmosphere to nitrtify surface and crystallize (Ta.sub.2 O.sub.5).sub.X-1 --(Al.sub.2 O.sub.3).sub.x layer.
27. The method, as defined in claim 1, wherein the top and bottom electrodes are made by selecting one metal among TiN, TaN, W, WN, Wsi, Ru, RuO.sub.2, Ir, IrO.sub.2, Pt and doped polysilicon.
28. The method, as defined in claim 1, wherein polysilicon or other metal is doped to form top and bottom electrodes by using PE-CVD method, RF magnetic sputtering method or LPCVD method.
29. The method, as defined in claim 27, wherein polysilicon or other metal is doped to form top and bottom electrodes by using PE-CVD method, RF magnetic sputtering method or LPCVD method.
Cooperative Patent Classification codes for this invention. Click any code to explore related patents in that topic.
Unknown
March 27, 2001
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